Electric furnace



Dec. 31, 1929. J. R. Evt-:s 1,741,411

ELECTRIC FURNAGE Filed Jan. 20. 1928 2 Sheets-Sheet 1 w.. www. wl m mwmx 1 l I I.

In velza I, C?

l l i ...E

Dec. 31, 1929. J. R. EvEs ELECTRIC FURNAGE Filed Jan. 20, 1928 2Sheets-Sheet 2 W. @NNI NW mw MNNER m .N

Nw vd.. N

llllillr NNN Patented lDec. 3l, 1929 UNITED STATES PATENT OFFICE JOSEPHR. EVES, OF BUFFALO, NEW ASSIGNOR TO lFALLS ELECTRIC FURNACECORPORATION, OF BUFFALO, NEW YORK, A CORPORATION OF NEW YORK ELECTRIC.'FU'RNACE Application led January 20, 1928.

This invention relates generally to electric furnaces but moreparticularly to that type including a platform for the material to beheat-treated which is movable into and out of 5 'the furnace.

One of its objects is to provide a simple and inexpensive furnace ofthis character having positive means for sealing the loadcarryingplatform in place and'thereby prevent un- 0 'due loss of heat and afforda saving in the consumption of electric power.

A further obj ect of the invention is to provide a trackless furnace ofthis type which is efficient and economical in operation and whichminimizes the expense of the load-carrying equipment used in connectingtherewith.

A still further object is the provision of simple means for supportingthe load-carry- Zoing platform in a position for effecting theadmittance of an even distribution of air to the furnace chamber for thepurpose of gradually cooling the charge.

In the accompanying drawings:

Figure 1 is a front elevation of an electric furnace embodying myinvention. Figure 2 is a vertical longitudinal section thereof on line 22, Fig. 1. Figure 3 is a transverse section on line 3 3, Fig. 2. Figure4 is a 0 `horizontal section of the furnace taken in the plane of line 1-4, Fig. 2. Figure 5 is a transverse section, similar to Fig. 3, showingthe work-carrying device in its elevated unsealed position. Figure 6 isa front end view of the Wheeled truck.

Similar characters of reference indicate corresponding parts throughoutthe several views.

In the preferred embodiment of the invention shown in the drawings, 10indicates the heating chamber and 11 the furnace body which maybeconstructed of any suitable refractory material. The heating chamber isclosed on all sides with the exception ofits front side, which is openand adapted to be closed by a vertically-movable door 12 suspended fromchains 13 and operated in any approved manner. Applied to the walls ofthe heating chamberare the resistor elements 14 which may likewise be'ofany well known Serial No. 248,175.

construction. As shown in Figs. 2 and 3, the heating chamber is disposedabove t-he fioor line to provide an air space or compartment 15 beneathit, and to this end the walls of the furnace. are supported on ametallic frame which may be composed of longitudinal and transverseZ-bars 16 attached to upright channel bars 17.

The bottom of the heating chamber is preferably in the form of a movableplatform or work-carrying device 18 which is capable of being movedlongitudinally into and out of a suspended position in the compartment15 thru the open front end of the furnace and which is adapted to bemoved vertically into and out of its operative position to effect an airtight, sealed bottom for said chamber or to permit the admission of acertain amount of air thereto for cooling the charge after its desiredheat treatment has been completed. This platform is made of structuralsteel and insulating material and supported on legs 19. Any suitablemeans may be employed for moving the platform into and out of its opereative position in the furnace, that shown in the drawings, by way ofexample, consisting of a well known type of wheeled truck 2O hav ing avertically movable member 21 which functions to elevate thework-carrying platform.

This movable member may be actuated in any suitable manner, for example,by pinions 31 engaging corresponding racks 32 depending from suchmember, whereby upon turning the operating crank 33, the movable memberis raised or lowered.

Extending around the side walls and rear Wall of the furnace adjacent tothe compartment 15 is a sealing trough upon which the platform 18 isadapted to seat in its operative position and thereby form an air-tightseal Valong these walls to eliminate heat losses within the furnace.This trough is preferably made of channel bars 22 containing sand orlike material and secured to the inner sides of the depending flanges 23of the Z-bars 16. Depending from the sides and back of the platform 18are sealing plates or aprons `211 which are adapted to enter thesand-filled channel bars in the operative position of the H5 portingtheplatform in-a Partially elevated platform shown in Figs. 1, 2 and 3, andtherey effectively seal the lower end of the fur nace chamber at itssides and back. For the purpose of sealing the lower front end of thefurnace, the platform is provided across its front endf with atransverse trough 25 constructedofachannel bar containingsand and thevertically movable door 12 is adapted to engage said trough in itsclosed position, as seen in Fig. 2; As shown in Figs. 1 and 4, thetrough-bar 25 on the platform extends laterally beyond the ends of thelongitudinal trough-bars 22 on the furnace which latter are disposedbelow the plane-of the former, so that when the platform is in itsoperative positionthelower endof the furnace chamber is sealediaroundits four sides.

In theuse of the apparatus thus far described, assuming the furnace door12to be open, the platform 18- is loaded with its charge andthensupported on-the truck 2O andwheeledinfan-elevated position into thecompartment 15 of the furnace, the elevating member 21v of thel truckbeing raised to such a height-asto allow the depending aprons 24 oftheplatform toc-lear the sand troughs 22 of the furnace, For the purposeof guiding the platform intoits compartn'ient, longitudinal guide rails26 may be provided which are attached to the upright channel bars 17 andare disposed below the furnace troughbars22: After thus beingmoved intothe furnace compartment 15, the elevating member ofthe truck is loweredto bring the platform-aprons 24 into engagement with the sand-troughsapplied tothel sides and rear end-of? the furnace, after which the door12 is lowered to Abring its lower end into engagement, with thesand-filled trough 25 on the front end ofthe platform. W7 ith the plateform'properly set in a suspended position to effectually sealthe furnacechamber 10, the truck'20-can beremoved and be utilized for use inconnection with other furnaces which may be ready for recharging ordischarging of'ftheircontents. In removing-the platform, the furnacedoor is opened and the truclr is wheeled'under said platform to raise itclear of the sealing troughs, after which it is pulled out of thefurnace on the truck and unloaded.

By providing a suspended load-carrying platform-and a sealing means ofthis character, the danger of losing sandfduring the insertion andremoval ofthe platform into and out ofthe furnace is eliminated, therebyassuring at all times a positive and effective sealy against heat lossesfrom the furnace chamber.

Ingorder to eect a gradual cooling of the charge after undergoingheattreatment, a

uniform distribution of air is adapted to be admittedaroundf'tlie foursealed sides of the platform 18. This is preferably accomplished byproviding an adjustable means for supposition to break its sealed oint.The means shown in the drawings consists of` longitudinal base rails 27disposed along opposite sides of the platform-compartment 15 of thefurnace and attached at their front and rear ends tohorizontally-foldable links. 281 pivotedtobase'plates 29. These baserails are adapted to be moved to a position for allowing the legs 19 ofthe platform to restthereon aiid'holdthe aprons 24'outoffsealingjengagement with the sand-troughs22, as sliown in Fig. 5.In seating the platform in'such position, it is first elevated therequired distance by thetiering truck 20, after which the base rails areshifted under the legs to support they platform, the truck being thenre,-

moved and usedy forl other duties.. This are;

rangement permits. of readily: breakingy the seal between the platform.and: the furnace and allows for the slow and even distribution-` of airthru all sidesof the heating'chamber:

This improved electric furnace provides for the efficient andeconomiehandling of'thematerials to be treated bye simple andinexpensive means which are soorganized andfarranged as to veffectually,seal the furnace against heat losses. while the materials are undergoingheattreatinent,.v and which provides for the gradualLcooling-oftliematerials by breaking such seal: andiadmittingfan even distribution`of air to the furnace chamber thru all sides thereof. constructioneliminates. the use of; expensive car and track equipment nowemployedinelectric furnace installations and materially reduces the operatingand maintenance costsv of such furnaces.

I claim as my invention.:

1. An electric furnace, comprising a'heating chamber open` at its bottomand having a door at its front end, a trough-shaped mein.-l bercontaining a sealing materiali` extending'f around the sides and' rearend of.7 the furnace chamber adjacentitsbottom, a wheelless carrier forthe material toibeheat-treated mov,-

able into and out ofthe furnace and formingr4 a closure for thebottomthereofl in its-oper` ative position, means for conveying'saidcarrier into and out of the furnace and-for; moving it vertically towardand fromthetroughshaped member, and aprons dependiiigffrom the sides andrear endof said wheellesscarrier for sealing engagement with thematerial in said trough-shaped member.

2. An electrio'furnace, comprisinga heating chamber open. at its bottom.and having,`

a door at its front end, a trough-shapedfmember containingvv a. sealing'material.. ext-ending around the sides andfrear end of the lfurnacechamber adjacent its fbottom,a wheelless carrier for the materialV tobeheatetreated movable into and out ofy the furnaceand forming a closurefor. operative position, means for"conveying@saidV carrier. in to and.out of the furnace, and for Furthermore, this the bottomA thereofvvinitsmoving it vertically toward and from the trough-shaped member,aprons depending from the sides and rear end of said wheelless carrierfor sealing engagement with the material in said trough-shaped member,and a second trough-shaped member containing a sealing material appliedto the front end of said carrier and arranged to be engaged by the doorin its closed position. 3. An electric furnace, comprising a heatingchamber open at its bottom and having a door at its front end, awheelless carrier for the material to be heat-treated movable into andout of the furnace and forming a closure for the bottom thereof, anupwardlyopening channel containing a sealing material extending aroundthe sides and rear end of the furnace and disposed below its open bottomand below the top of said carrier, aprons depending from the sides andrear end of the carrier and engageable with the material in said channelfor sealing the joint between said carrier and the furnace, and restsdisposed in the bottom of the furnace and movable into and out of anoperative position for supporting the carrier in a partially elevatedposition for breaking such sealed joint.

4. An electric furnace, comprising a heat- 3o ing chamber open at itsbottom and having a door at its front end, a conveying device for thematerial to be heat-treated movable into and out of the furnace andforming a closure for the bottom thereof in its operative position,means for sealing the joint between said conveying device and theadjoining walls of the furnace, means for temporarily elevating saiddevice for breaking said seal to admit air to the heating chamber forcooling the material undergoing heat-treatment, and means applied to thefurnace for supporting the device' in its elevated position.

5. An electric furnace, comprising a heating chamber open at its bottomand having a door at its front end, a wheelless carrier for the materialto be heat-treated movable into and out of the furnace and forming aclosure for the bottom thereof, upwardlyopening channels containing asealing material extending around the sides and rear of the furnace anddisposed below the top of the carrier, aprons depending from the sidesand rear end of the carrier and engageable with the material in saidchannel for sealing the joint between said carrier and the furnace, andsupporting rails adjustably mounted at the sides of the furnace forsustaining the carrier in a position to break the seal between it andthe channels.

JOSEPH R. EVES.

